Pneumatic hammer.



No. 834.187, PATENTE-D 00T. 23,' 1906. o: T. GARNAHAN.

PNEUMATIQ HAMMER-. APPLICATION FILED MARAQ 1906.

Y l v hm@ of Colorad zo motive Huid, which rwoul UN'rrED STATES -,PATEivII OFFICE.

' CHARLES T. CARNAHA, OF DENVER, COLORADO.

RNEUMATIC HAMMER.- l

Specification of Letters Patent. n

Application filed MarchQ, 1906. Serial No. 305.171.

Patented Oct. 23, 1 906.

To 4all whom', it may concern,.-

Be itknown thatl, CHARLES T. CARNA HAN, a citizen of the United States, residing at Denver, in the county of Denver and State o, have invented new and useful In rovements kin Pneumatic Hammers, of

whlch the 4following is a specification.

This invention relates to percussive devices, more particularly that -c a re erred to, for automatically discontinuing .r 5 the operation of the hammer of the drill,

when the tool of the drill `is not positioned so as to receive the blow of the hammer, thereby preventing' the unnecessary operation of the drill and obtaining a eat saving ofthe dgl. not be the case if the hammerwas continually operated with.- out striking -the shank of the tool.

The invention further aims to provide a pneumatic' drill with `means as hereinafter z5 set forth to'v'prevent damage to the tool- 3o and in this connection it wil through carelessness on the part vof ano erasocket or bushing when the shank of the-tool is not in position to receive the blows of the hammer, as in such instance the blows of the hammer fall upon the bushinor or tool-socket,

libe stated that ltor it often happensthat the bodyo the drill is not held firmly up againstthe tool, so

, that the shank of the tool will not receive the 3 5 blows ofthe hammer.

It is a well-known fact that an o erator often positions the 4o the blows of the pneumatic drills now in genera use.

body of the dri with res ect to the tool so that the shank of the too does not project beyond the bushin vor tool-socket to receive ammer, and when ositioned in such manner the hammer recipro-4 cates, .striking the tool-socket or bushing and causing a great deal of-damage, such objection being the 4greatest difficult With vthe Be.- side this, when the hammer is allowed to re ciprocate in a' manner as stated-.thatis-,to say', so as not to impart, blows to the shank ofthe tool-such reciprocation of the hammer 5o is using up any uantity of the motive fluid without beneficia results and also the operator is wasting his time. In mines it is not possible for a` foreman oisuperintendent to eep his eye on all the4 operators, as it is in other classes of Work, and the `foreman or superintendent generally depends on sound ass of percusl xo sive devices styled pneumaticdrills which n.

pneumatic drill with means, as hereinafterl to see the operator; but by providing a drill of the class referred to wit means as hereinafter described the :operator cannot cause a reciprocation of the hammer unless the tool is drilling or boring rock.

A further advantage obtained by providing a drill'of the class` referred to with means as hereinafter described it will not/ necessitate the operator manually -shutting oil' the motive-fluid suppl to discontinue the operation of the drill w. en the opcrator'wishes to discontinue the drillinfr or boring to clean up the hole or for some ot ier/reasonv` It is gem erally the case thatwwhen the operator desires to clean up the hole when thc drill is set up,

or for some other purpose, after the motive fluid is cut off I.the operator throws the drill down in the bojttomof the drift Where lfrom the movementlbf the o erator himself ste ping around (ir from tlie movement of t e motive-fluid hose or from'some other cause the valve will/often be opened again andthe drill started to operate-While in the position set. :When it does operate in vsuch manner, y

it jumps aroii'nd over the bottom of the drift and causes'a great deal of-trouble to theoperator. to catch holdl of it vand stop the operation thereof. .When it is desired that the operator discontinue the' reciprocation of the hammer or the o eration of the drill, all that is-necessary 4is -or the -o erator to lift .the body portion of the dril :off the tool, and such action on. the part of theoperator will cause the automatic discontinuing of the operation ofthe drillhand there is no danger of the drill again operating until it is laced on the shank of the tool so'that said s ank will be positioned to receive the blows of the hammer of the drill.. w. l

ICO

The inventioniurther aims to provide a". pneumatic -dri-llwith means as hereinafter l referred to. and for the purpose set forth which shall be simple in itsv construction. and

arrangement, strong, durable, e'llicient in its use, and comparatively inexpensive when setting up the same in connection with the drill. l

With the foregoing and other objects in view the invention consists of the novel eonstruction, combination, and arrangement of parts hereinafter morespecifically described, and illustrated in the accompanying drawings, Which form a part of this specification, and wherein is shown the preferred einbodiment of the invention; but it is to be understood that changes, variations, and modifications can be resorted to which come within the scope of the claims hereunto appended.

In describing the invention in detail reference is had'to the accoiiipaiiying drawings, wherein like reference charaeters denote corvresponding parts throughout the several views, and in which-- I Figure 1 is a vertical section of the cylinder of a pneumaticI drill constructed in accordance with this invention. Fig.v 2 is a View similar to Fig. 1, biit broken away at each end, showing the hammer at its lower-most position. Fig. 3 is a side elevation of a reeiprocatoryr hammer.

Referring to the drawings by reference characters, 1 denotes the cylinder or body portion of the drill, closed at one end by a cap 2 or othersuitable means and at its other end provided with a screw-thi'lr-iaded bushing 3,

' constitutiiiga tool-siwket and having exterior screw-threads engaging 'interior screw threads formed on the inner face of the cylinder. The bushing 3 has its inner face formed With an annular shouldei4, against which is adapted to abut a corresponding shoulder formed on the shank 5 of the tool 6. ner face of the cylinder 1 is formed with a recess 7, constituting a motive-fluirl-receiving With the wall thereof screw-threade( Communicating with the primary motive- Huid-outlet chamber is the motive-fluid outlet 11, which is formed in the Wall of the cylinder 1. The portions indicated by the ref erence characters 12 13 of the inner face of the cylinder 1 are of the same diameter, and the portions 14 -15of the inner face of the cylinder 1 are also of the saine diameter; but the said portions 14 15 are of less diameter than the portions 12 13, and thereby there is formed at the junction of the iortion 14 with the portion 13 a shoulder 15 or a purpose to be hereinafter referred to. rlhe wall of the `cylinder 1 is formed with a plurality of passages 16, which communicate at their upper The in-y ends with'the chamber 8 and at their lower ends open into the chamber 9. The functionof the passages 16 will be hereinafter referred to.

The hammer of the drill is indicated by the reference character 17 and is constructed of two different diameters, the major portion of which being of less diameter than the remaining portion, said major portion being indicated by the reference character 18 and. the remaining portion by the reference character 19. `By constructiner the hammer in a manner as stated a shou der 20 is formed at the junction of the portion 18 with the portion 19 of the hammer 17. The diameter of the portion 18 is substantially equal to that of the di; aineter of either of the portions 14 15 of the inner face of the cylinder 1, and the diameter of the portion 19 of the hammer 17 is substantiallyl equal to that of either of the portions 12 13 of the inner face of the cylinder l. The hammer 17 is formed with a chamber, which extcndsfroni the end of the portion 19 of the hainin`er`17 and terminates at a point removed from the free end of the portion 18. The porlioii'lS is forincd with a plurality of ports `22, lying in different planes and which o en iii-to the chamber 21 and constitute out etports for said chamber. The portion. 19 of the hammer 17 is formed with a plurality of ports 23, which open into the chamber 21 and consti tu te inlet-ports for said chamber 21.

The manner in which the reci rocation of the hammer 17 is automatically iseontinued is as follows: In drills of the-character re-l ferred to the shank 5 of the tool 6 is of such length as t'o project above the'inneredge of the bushing 3, so that said shank will receive the blows of the hammer. If the shank does not project above the inner end of the bushing 3, then the inner end of the bushing receives the blows ofthe hammer. N ow it will be assumed that the shank 5 extends inwardly in the cylinder 1 at a point above the inner end of the bushing 3, and when in such position andthe hammer reciprocates in one direction the hammer strikes the end of the shank and stops at a point so that the motive fluid in the chamber 21 will exhaust through the ports 22 into the chamber 8, and a part of the exhaust will then pass through the assages 16 into the chamber 9 and from sai chamber through the axial bore in the tool. Now it will be assumed that the shank ofthe tool is positioned in such a manner that it does not extend inwardly such a distance so that it will be in the path of the hammer to receive the blows thereof. Therefore when the hammer is reciprocated Iin one direction it Will strike the inner end of the bushing 3, and when in this position the ports 22 will be closed by that portion 15 ofthe cylinder-1. The hammer 17 will then be positioned in the cylinder 1 so that the ports 23 will o )en into the chamber 7. The motive Huid w ich is then admitted IOO IIO

l l l hammer down on the bushing, thereby auto- 3 maticallyy stopping the rcciproeation ol" tho hammer.' Now if the body portion of the .I

drill he. pushed down on thetool, so that the too-l will extend above the hushing 3, which at the same time will force the hammer in an opposite direction, the ports 23 are pushed clear of the. chamber 7, and th( ports 22 will then open into the chamber S and the motive fluid exhausted. At this )osition the shoulder 2U is then in the cham )er 7, and the ham- ;ner makes its return strokeo\\'ing to the pressure of the motive ilui'd on said shoulder 20, and moves in a return direction until ports 22 open into the chamber 7, so lthat the incoming motive fluid will pass through said )orts 2) into said chamber 21 and above'the ianuner and cause the movement of the hammer in -an opposite direction.

lt will he observed that when the tool is removed, or rather the shank of the tool is not in position to receive the blows of the hammer, the shoulder 2() must pass the chamher 7, and consequently compress the motive tluid ahead of it, which is evident, owing to the arrangement of the shoulder ll on the inner face of the. cylinder 1 and also as there is no outlet for the motive tluid. Such action eushions the blowo'n the bushing, so that the hammer does not come down very hard theeron. This is necessary, for il the hlow of the hammer was not cushioned and the hammer should 'strike the bushing 3 very hard it.- would rebound, and consequentlyv the reciproeation of the hammer would not be discontinued.

Having' thus fully described my invention, what I claim as new, and desire to secure by Letters Patent., is-

l. A pneumatic drill comprising a cylinder )rovided with a in()tive-iluid-reeeiving chamlier, a primary motive-iluinl-exhaust cham- Aber, a second motive-iluid-exhaust chamber, passages for establishing communication hetween the two exhaust-chainhers, an exhaust. vfor the primarjv exhaust-chamher, an inlet for the reeeiving-chaml1er, and a ehumhered hammer-provided with inlet and. outlet ports adapted to communicate with the reeeivingchamber and one ol the exhausti11g-chambers. y

2. A pneumatic drill comprising a cylinder nrovided with a niotive-l'lui(l-reeeiving chamlier, a primary motive-fluid-exhaust chamber, a second motive-thml-exhaust ehamher,

passages for establishing communication heoutlet-ports for thechamher therein, said outlet-ports lying in dillerent planes and adapted to communicate with" the receivingchamber and one-ol the exhausti11g-chainhers. i

3. A pneumat ic drill comprising a cylinder provided with a motive-fluid-receiving chamher, a primar)Y motive-fluirl-exhaust chamher, a. second nntive-luid-exhaust chamber,

passages tor estal)lishing'communication he-A tween the two exhaust members, an exhaust tor the primary exhaust member, an inlet f'Or the receiving-chaniher, a chamhcred hammer provided at one end with inlets for the chamber therein and at its other end with outlet-ports l'or the chamber therein, said outlet-ports lying in dill'erent planes and adapted to communicate with the receivingchamber and one of the exhausting-chamhers, and means forming 'a part of the cylinder and hammer for cushioning the stro 'e of the hammer for the purpose set forth.

. 4. A pneumatic drilleomprising a c vlinder provided with an inlet', a mir ot exhaustehamhers, passages for estalilishing communication hetweenthe two'exhaust-chambers, an outlet for one of said exhaust-chambers, and a ehamhered hammer provided with inlet and outletports ad'a]' ted to communicate with the inlet of said cylinder and one of the exhaust-chainhers.

5. A pneumatic drill comprising a cylinder provided with an. inlet., a air of exhaustchambers, passages for estahlishing communication between the two exhaust-chamhers, an outlet for one of: said exhaust-chambers, and a chambered hammer provided with inlet and outlet ports adapted to communicate with the inlet of said cylinder and one of'the exhaust-ehamhers, in lcombination with a tool having an laxial bore communicating with one ot' the exhaust-chambers.

6. A pneumatic drill comprising a cylinder provided with an inlet, apriniary exhaustchamber, a second exhaust-chamber, passages tor establishing communication hetween the two exhaust-chambers, an outlet lor the primary exhaust-chamber, and. a. chamhered hammepmvided at one end with inlet-ports for the chamber thereinand at its other end witlroutlet-ports for the chamber therein, said outlet-ports adaptedtoeommu- IOO IOS

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Anieate with the inlet of the cylinder and with one of" said exhaust-cham'bers and said. inlet- )orts adapted to communicate with the inlet ot the cylinder. v

In testimonywhereof IA have hereunto set my hand in presence of two subscribing witllCSSCS.

CHARLES T. CARNAHAN. Witnesses f J. M. SCHUMESER, DANIEL MURPHY. 

